A heat pump energy-saving process method for the cyclohexanone unit in a caprolactam plant

Abstract

The present invention discloses a heat pump energy-saving process method for the cyclohexanone unit in a caprolactam device. The benzene separation column and the benzene recovery column are pressurized, and then the gaseous phases at the tops of the benzene separation column and the benzene recovery column are directly compressed. After being pressurized and heated, they are respectively supplied for heating the bottom of the cyclohexene separation column. The temperature of the condensed liquid phase is relatively high. The two heat pump condensate liquids are exchanged heat with the steam condensate liquid flashed to 110°C to generate 110°C saturated steam. After being pressurized by the steam heat pump, it is incorporated into the 0.5 MPaG pipe network for use, and its own temperature is reduced to 120°C. After being cooled by the aftercooler, it enters the reflux drum for reflux. The steam consumption at the bottoms of the benzene separation column, the benzene recovery column, and the cyclohexene separation column in the cyclohexanone unit is relatively large. In the present invention, the gaseous phase of the distillation column with a lower temperature level is pressurized to heat the bottom liquid, so that the energy can be fully utilized, the consumption of public works is reduced, and the economic benefits of the cyclohexanone production unit are improved.

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